This is a five year CCSG renewal (years 24 through 29 requested) for the 298 member Jonsson Comprehensive Cancer Center at UCLA. Major changes have been introduced into the Cancer Center to strengthen clinical research, foster increased collaboration and promote translational research, since the arrival of the new Director, Judith G. Gasson, P.h.D. in September of 1995. Changes in the Program Areas include a new program in Signal Transduction in the Division of Basic Research and complete re-organization of the Clinical/Translational Program Areas into: (i) Breast and Women's Reproductive Cancers, (ii) Hematopoietic Malignancies, BMT and Stem Cells, (iii) Prostate Oncology and (iv) Solid Tumor Oncology. In addition, the program areas in the Division of Prevention and Control Research have been re-organized into Healthy and at-Risk Populations and Patients and Survivors. Renovation and creation of over 19,000 square feet of new laboratory space, along with completion of the second competitive cancer center space review facilitated the recruitment of fifteen outstanding new faculty and allowed the re-assignment of space within the building based upon merit and to facilitate productive interactions. Clinical Research has been strengthened considerably by increased space and support for the Clinical Research Unit. Accrual of patients to clinical trials has increased substantially and the quality of research has been improve by implementation and subsequent approval of our Clinical Protocol Review and Monitoring System. A Clinical Trials Development has been established to facilitate the conduct of phase 1 trials, particularly those arising from translational research within the Cancer Center. Finally, a community based/UCLA Oncology Research Network has been established throughout Southern California to provide state-of-the-art care and access to clinical trials to patients in their local communities.